This invention relates to a recording apparatus, a file management method, a program for a file management method and a recording medium having a program for a file management method recorded thereon and can be applied typically to an optical disk apparatus.
In recent years, disk apparatus and the like have been proposed which use a randomly accessible recording medium having a large capacity such as an optical disk.
A method is disclosed, for example, in Japanese Patent Laid-Open No. 2001-84705 (hereinafter referred to as Patent Document 1) which uses such a disk apparatus as described above to improve the operability in operation of a large number of files. According to the method of the Patent Document 1, an index file for indexing a large number of files recorded on a recording medium is produced from the large number of files and recorded on the recording medium. The large number of files on the recording medium can be operated using the index file.
Japanese Patent Laid-Open No. 2002-278996 (hereinafter referred to as Patent Document 2) discloses a method which further improves the operability in operation of a large number of files recorded on a recording medium. According to the method of the Patent Document 2, an index file produced in such a manner as described above manages the files hierarchically.
In the methods described above, an index file is composed of a part of actual data which collectively includes extract information formed by extracting information relating to a management object file and so forth and another part of management data which collectively includes position information and so forth necessary for accessing to the actual data.
Referring to FIGS. 9A to 9D, the actual data part is composed of a sound entry E1, a text entry E2, a thumbnail picture entry E3 and a property entry E4 which are data sets which collectively include extract information classified for individual types into groups. The sound entry E1 has allocated thereto a disk title and extract information of audio data for a short period of time representative and contents of management object files. The sound entry E1 includes a sound entry header SH set at the top thereof and representing that the entry is the sound entry E1 and a sequence of sound entry slots SES0, SES1, SES2, . . . each including extract information collected as a block.
The text entry E2 has allocated thereto the disk title and extract information of a character sequence of management object files. The text entry E1 includes a text entry header TXH set at the top thereof and representing that the entry is the text entry E1 and a sequence of text entry slots TEXS0, TXES1, TXES2, each including extract information collected as a block.
The thumbnail picture sensor E3 has allocated thereto the disk title and extract information of still pictures representative of contents of the management object files. The thumbnail picture sensor E3 includes a thumbnail picture entry header THH set at the top thereof and representing that the entry is the thumbnail picture entry E3 and a sequence of thumbnail picture entry slots THES0, THES1, THES2, each including extract information collected as a block.
In contrast, the property entry E4 has allocated thereto the disk title and data representative of properties of the management object files and has allocated thereto extract information of binary data which are set to the management object files. The property entry E4 includes a property entry header PH set at the top thereof and representing that the entry is the property entry E4 and a sequence of property entry slots PES0, PES1, PES2, . . . each including extract information collected as a block.
Consequently, for example, when a desired file is to be selected with reference to thumbnail pictures, when a file is to be selected based on titles, or in some other case, the index file can provide extract information set to a corresponding one of the entries E1 to E4 to the user in accordance with a selection criterion of the user so that the user can select a desired file simply, easily and with certainty.
Incidentally, where extract information is classified for different kinds of property information into groups to form the entries E1 to E4 in this manner, depending upon the type of the management object file, also such a situation possibly occurs that, although a corresponding slot is present in the property entry E4 without fail, no corresponding slot is present in some other entry or entries. Thus, it is expected that, if each of the slots of the property entry E4 has recorded therein management information for managing the slots of the property entry E4 and the corresponding slots of the other entries and the slots recorded in the other entries E1 to E3 are referred to in accordance with the management information as indicated by arrow marks in FIGS. 9A to 9D, then the management of the extract information can be simplified.
Further, if one of the different kinds of management information to be set to each of the slots of the property entry E4 is flags which individually represent whether the slot itself and corresponding slots of the other entries are valid or invalid and the flags are set so as to indicate that they are free or empty slots, then if only the flags are suitably operated upon deletion of a management object file, then the corresponding extract information can be deleted from the index file. Consequently, it is expected that management relating to the index file can be simplified.
Further, in the index file described above, since the length of the extract information sometime varies, it is expected that, if the slots of the index file are formed with a fixed length and extract information relating to one file is allocated to one or a plurality of slots while free or empty slots are allocated to the entries taking such variation of the extract information into consideration, then possible wastefulness when the entries are recorded on a recording medium can be eliminated and a drop of the processing speed can be prevented effectively. In particular, if the measures described above are taken, then even if the number of management object files varies, logical positions and physical positions of the entries on the recording medium can be allocated to individually continuous regions, and consequently, the index file can be read out at a high speed.
However, where the measures described above are taken, a great number of free or empty slots may appear in the index file, and in a process of reading out the index file from the recording medium, useless slots may be read out in vain. Further, for example, where all of the slots of the property entry are read out and stored into a memory and a management object file is processed with reference to the index file stored in the memory, the information of the free slots is recorded wastefully in the memory, and the capacity of the memory is consumed uselessly.
One of possible solutions to the problem just described is to record the number of valid slots in the property entry header. In this instance, however, while data of the property entry is read out from the recording medium, it is necessary to discriminate the flag set in each of the slots thus read out to count the number of valid slots. Therefore, a longer period of time is required for the reading out of the property entry as much.
It is to be noted that, where the data of the property entry is read out from the recording medium in this manner, since the reading out process is performed upon starting of the pertaining apparatus, an increased period of time as much is required for the starting of the apparatus. The waiting time upon such starting appears conspicuously where the apparatus is a recording apparatus which requires a comparatively long period of accessing time like an optical disk apparatus.